When immunologist Dr Deborah Burnett contracted pneumonia, antibiotics saved her life.
“I went from struggling to breathe to significant improvement after half an hour of IV antibiotics,” she says. “If my bacteria hadn’t been susceptible to antibiotics, I know for a fact I’d be dead.”
Leader of the Protective Immunity Group at the Garvan Institute of Medical Research, Dr Burnett and her collaborators use new technology to advance vaccine development. With more and better vaccines, researchers hope to mitigate the growing antimicrobial resistance (AMR) to safeguard antibiotics like the one that cured her infection.
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We’ve entered the era of vaccines. Prevention is better than cure.
Dr Deborah Burnett
Vaccines and antibiotics: what’s the difference?
They are two extraordinary breakthrough therapies that have saved millions of lives. But vaccines and antibiotics work in totally different ways.
When you contract a serious bacterial infection, antibiotics target and kill the invading microbe. If that infection returns, drugs could be deployed to do it again.
Vaccines train your immune system to hunt down invaders to prevent disease. The protection they confer varies in duration but for some diseases – measles, for example – vaccine immunity can be lifelong.
“A good vaccine is one that you’ll never fully appreciate: if it’s doing its job, then the disease isn’t a problem,” says Dr Burnett.
Aren’t antibiotics used for bacterial infections and vaccines for viruses?
Antibiotics can be used to treat bacterial infections. Antibiotics won’t help, for example, if you contract a gastrointestinal virus. While most vaccines prevent viral, fungal or parasitic infections, some target bacteria, like meningococcal and tuberculosis vaccines.
One of the main reasons there aren’t more vaccines available for bacterial infections, according to Dr Burnett, is that there hasn’t been a need for them. Affordable, accessible and highly effective antibiotics have carried the load for decades but, unfortunately, we can no longer expect all bacterial infections will be susceptible to antibiotics.
If antibiotic use continues to be the main way we combat bacterial infections, it’s likely that AMR will increase. Luckily, there’s no significant reason that vaccines can’t share the load.
“Vaccines are expensive to develop and it’s impossible to make one that will cover all bacteria; they have to be carefully targeted. Why would you spend resources developing vaccines when something else could do the job?” she says.
“But we don’t want to wait for a situation where human life expectancy returns to the pre-antibiotic era. We need an alternative to antibiotics now, and vaccines can fill that need.”
Targetting bacteria to fill the antibiotic gap
Group A streptococcal bacteria cause the common childhood ailment strep throat. Without diagnosis or treatment with antibiotics, however, serious infection can lead to acute rheumatic fever (ARF) or rheumatic heart disease (RHD) and cause cardiac damage.
Australia’s First Nations people, especially children, bear the devastating burden of RHD, which affects health and life expectancy. Between 2016 and 2020, the number and rate of ARF notifications in Australia increased, with Aboriginal and Torres Strait Islander peoples accounting for 92% of cases.
A vaccine for strep throat could all but eliminate RHD, providing affordable, long-lasting protection and ease the need for diagnostics and antibiotics in remote or disadvantaged areas with limited access to medical care.
For common bacterial infections, especially those that cause recurring or chronic conditions, vaccination could become the go-to defence that reduces the burden on healthcare systems. Concerns about appropriate doses and matching medicine to microbe could also diminish.
Urinary tract infection (UTI) results in more than 2.5 million GP visits and costs the community hundreds of millions of dollars a year. Treated with broad spectrum antibiotics, which contribute to AMR, many UTIs occur in hospital. But vaccines to target hospital-acquired UTI are in development, with the potential to save 2 million hospital days annually.
Vaccines also ensure a heathier population, which needs fewer antibiotics to fight secondary infections.
So new vaccines will save the day?
For every success story, like the polio vaccine created in the 1950s which has all but eradicated the disease, there are countless failures. But new technologies are boosting the odds, making vaccines faster and cheaper to produce.
“Instead of a pipeline where a vaccine took 15 years, $250 million and failed 90% of the time, we can now quickly make 10 to 20 different vaccine candidates at once, figure out which one is the real-world best, and then take it further,” says Dr Burnett.
The mRNA technology that proved a lifesaving defence against COVID-19 is expected to contribute to next-gen anti-bacterial vaccines. Australia has invested heavily in mRNA development and manufacturing facilities which, when completed, will enable sovereign vaccine production.
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Without action now, there will be trouble.
Dr Robin Achari
Australia’s poultry industry: a vaccine success story
Unlike many overseas counterparts, the Australian poultry industry is largely antibiotic free and, as such, contributes very little to the growth of AMR.
Vaccines are key to this success according to Dr Robin Achari, senior technical vet at Melbourne-based BioProperties Australasia. He troubleshoots the use of two live vaccines across more than 75 countries to protect chickens against respiratory disease caused by Mycoplasma synoviae and Mycoplasma gallisepticum bacteria.
Unlike humans, farmed chickens have been vaccinated against bacterial infection for decades, creating healthier generations of breeding stock, preventing transfer of bacteria from chickens to consumers and reducing AMR.
Thirty years ago, antibiotics were routinely added to chicken feed to prevent disease. In Australia, Dr Achari says, they’re now used sparingly and, combined with vaccination, good animal husbandry practice and biosecurity measures, rarely needed.
“The future is vaccines,” Dr Achari says. “I’m seeing an increase in the level of resistance that is developing in bacteria overseas. Without action now, there will be trouble.”
Michelle Fincke is a Melbourne-based freelance journalist and editor. She has spent the last two years working with case studies and writing in the public health space.
